gwr
Involved Member
Posts: 56
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Post by gwr on Nov 5, 2009 13:13:56 GMT
Hello, I have been trying to source some sulphuric acid to pickle a boiler under construction, and my source has given me some 15% hydrochloric acid. Whilst i know this very nasty stuff would it be suitable for use with copper / sliver solder to clean prior to silver soldering. It may be a daft question for those in the know, but as i have all the safety ppe and the hydrochrolic acid is free, i thought i'd ask.
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brozier
Part of the e-furniture
Posts: 335
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Post by brozier on Nov 5, 2009 14:48:11 GMT
Hi GWR,
Not sure about using Hydrochloric but I use the high strength drain cleaner (usually 98% Sulphuric) as a cheap source of pickling acid. Dilute 10:1 or weaker....
Cheers Bryan
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russell
Statesman
Chain driven
Posts: 762
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Post by russell on Nov 5, 2009 16:20:57 GMT
I am no chemist but I believe the preference for sulphuric acid to be because it doesn't dissolve the base metal as rapidly as hydrochloric. You want to remove the flux and the oxides, not the copper itself! Remember if you buy strong sulphuric acid ALWAYS add the acid to the water when diluting, not the other way round.
Russell.
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weary
Part of the e-furniture
Posts: 290
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Post by weary on Nov 5, 2009 19:52:53 GMT
I get my Sulphuric Acid from a car parts shop (they also sells batteries). The acid comes in one litre plastic bottles and is 37% strength. Marketted under the name 'Banner'.
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Post by drainblocker on Nov 5, 2009 20:09:24 GMT
Draincleaner. It does a great pickle, can be bought from most hardware shops or builders merchants. When it has done its job, tip it down a manhole and it will keep the drains clean. I should know.
DRAINBLOCKER
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Post by havoc on Nov 5, 2009 20:27:31 GMT
I got mine at the car shop as well. It is used in batteries after all. Din't bother to dilute. Strange that draincleaner is acid in the UK, here in Belgium it is concentrated NaOH. But that can be used for develloping pcb's
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Post by Shawki Shlemon on Nov 6, 2009 8:04:58 GMT
I get mine from car spare parts shop but i dilute it with two parts of water to give me approximately 10% strength .
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Tony K
Elder Statesman
Posts: 1,573
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Post by Tony K on Nov 6, 2009 8:42:48 GMT
From a previous thread hereEmphasise Baggo's comment about the dilution of drain cleaner. Blackgates supply the real thing, but probably collect only.
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abby
Statesman
Posts: 927
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Post by abby on Nov 8, 2009 1:39:11 GMT
Hydrochloric fumes quite a lot and if kept in your workshop will cause rust to form quickly on your tools , just like Bakers fluid for soft soldering.
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Post by maninshed on Nov 10, 2009 13:59:25 GMT
I've seen the drain cleaner stuff at my local Ironmongers 98% sulphuric 1 litre £9.98. They also had one with the hydroflouric in think i'd go for the sulphuric.
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Post by jgb7573 on Nov 11, 2009 21:27:46 GMT
Good choice. From what I remember, hydrofluoric is nasty stuff indeed.
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Post by durhambuilder on Nov 11, 2009 21:47:00 GMT
I have previously used drain cleaner but my batch seemed to leave a black greasy film on the copper , I'm now using citric acid crystals, you can purchase these by the kilo in any home brew shop, it may take a few minutes longer but it certainly won't do me too much harm
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